Electric storage batteries commonly used in many automobiles or motor vehicles have the ground and positive terminals located on the side of the battery; and in this disclosure, such are to be referred to as side-mount batteries. Each terminal has a threaded tap, so a bolt can be fitted through a connector eyelet in a battery cable and be threaded into the tap, to provide a mechanically secure and electrically sound connection between the cable and terminal.
When a primary vehicle battery is low in charge, and/or when the engine itself is under high load starting conditions (such as in cold winter weather), a jump start frequently can be needed and made. In order to do this, a secondary battery or source of electrical power is temporarily connected by jump cables to the battery terminals (or sometimes to the grounded engine frame). Typically, each end of the jump cable has an alligator type clamp to allow for making this temporary and separable connection.
However, it frequently is quite difficult to secure the alligator clamp in place onto the battery terminal bolt of a side-mount battery, because: (1) of tight space constrains next to the battery; and moreover (2) typical side mount battery terminals are quite small and have little structure to clamp onto. Thus, the alligator clamp of the jump cable frequently may be unstable, and quite readily can slip off the terminal bolt.
The consequences of a battery cable clamp coming off the battery terminal can be quite devastating, should the cable clamp be live and complete a short circuit against any grounded portion of the vehicle frame or engine, and/or be the ground and complete a short circuit against the live other cable. This would create a dead short, with accompanying intense arcing; and such potentially could be very damaging and/or dangerous.